JPH038662B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for producing cellular materials.

BACKGROUND OF THE INVENTION It is already known that when producing a cellular material, Si-bonded hydrogen is eliminated by reaction with a hydroxyl group-containing compound, thereby creating voids in the cellular material. In this regard, for example, British Patent No. 867619 [Published on May 10, 1961]
Midland Silicones
Silicones).

Problems to be Solved by the Invention By the way, when a cellular material is produced by reacting a Si-bonded hydrogen-containing compound with a hydroxyl group-containing compound, the problem arises of obtaining a particularly dimensionally stable form in a particularly short time. Ta. This problem is solved by the present invention.

Means for Solving the Problems The object of the present invention is a method for producing a foam material by reacting a Si-bonded hydrogen-containing compound with a hydroxyl group-containing compound, in which the Si-bonded hydrogen-containing compound is , a process for producing a cellular material, characterized in that a material is used which, at least in part, has both Si-bonded hydrogen and at least one SiC-bonded group with basic nitrogen in the same molecule.

The organopolysiloxanes used in the process according to the invention may be linear, branched or cyclic.

^The organopolysiloxanes with Si- _{bonded hydrogen used} according to the invention preferably _have ^the formula _: ,
represents a SiC-binding organic group free of basic nitrogen, R ¹ represents a monovalent SiC-binding group containing basic nitrogen, which may likewise be the same or different, and R ² represents a group 1
each represents the same or different alkyl groups having 1 to 4 carbon atoms, x is 0, 1, 2 or 3, on average 0 to 2, preferably on average 0 to 1.8, y is 0 or 1, Average is 0.1 to 0.6, preferably average is 0.15 to 0.3, and z is 0 or 1, average is 0.2
~1, preferably on average 0.5~1, p is 0,
1, 2 or 3, average 0-0.8, preferably average
0.01 to 0.6, and the sum of the respective average values of x, y, z and p is at most 3.4].

Examples of Si-bonded organic groups R that do not contain basic nitrogen are:
In particular hydrocarbon radicals having 1 to 20 carbon atoms per radical, such as methyl, ethyl, n-propyl and isopropyl radicals, and alkyl radicals such as octadecyl; vinyl and allyl radicals and butadienyl radicals; at least 1 like
Aliphatic hydrocarbon groups with two double bonds; cycloaliphatic hydrocarbon groups such as cyclohexyl and methylcyclohexyl; aromatic hydrocarbon groups such as phenyl and naphthyl; alkaryl groups such as tolyl and aralkyl groups such as benzyl groups. The hydrocarbon radicals can have substituents that are inert towards Si-bonded hydrogens, basic nitrogens and hydroxyl groups at temperatures below 50°C. Examples of substituted hydrocarbon groups of this type are 3,
Fluorinated hydrocarbon groups such as 3,3-trifluoropropyl; 1,1,2,2,3,3-hexafluoropropyloxypropyl and 1,
Monovalent aliphatic groups composed of carbon atoms, hydrogen atoms, ether oxygen atoms and fluorine atoms, such as 1,2,2-tetrafluoroethoxypropyl group, and p-methoxyphenyl group, It is a monovalent hydrocarbon group containing ether oxygen as the only substituent.

Particularly because of their easy availability, the basic nitrogen-free SiC-bonded organic groups in the organopolysiloxanes used according to the invention are preferably methyl groups. Furthermore, it is advantageous if a hydrocarbon group, in particular a methyl group, is also bonded to each silicon atom to which a hydrogen atom is directly bonded.

SiC bonding group with basic nitrogen and thus the group R ¹
for the formula: R ³ ₂ NR ⁴ − [wherein R ³ represents hydrogen or the same or different alkyl group or amino group or iminoalkyl group, and R ⁴ represents a branched hydrocarbon group; [expressed] is advantageous.

Examples of alkyl radicals R include, within the entire scope, alkyl radicals
This also applies to ^R3 . However, it is preferred that at least one hydrogen atom is bonded to each nitrogen atom in the group of the formula: R ³ ₂ NR ⁴ -.

Preferably, the branched hydrocarbon radicals R ⁴ have at most 20 hydrocarbon atoms per radical. Examples of hydrocarbon groups of this type are methylene and ethylene groups, as well as propylene, butylene, cyclohexylene, octadecylene, phenylene and butenylene groups. Particularly preferred is the n-propylene group because of its easy availability. As the SiC bonding group with basic nitrogen, and therefore the group R ¹ ,
Particular preference is given to radicals of the formula _H2N ( _CH2 ) _2NH ( _CH2 ) _3- .

Another example of a SiC bonding group with a basic nitrogen and thus a group R ¹ is of the formula: H ₂ N(CH ₂ ) ₃ − H ₂ N(CH ₂ ) ₂ − H ₃ CNH(CH ₂ ) ₃ − H ₂ N( _CH2 ) ₅ -H( _{NHCH2CH2 ) 3- and} n- _C4H9NH ( _CH2 ) _2NH ( _CH2 ) _3- .

Examples of radicals R ² are, in particular, the methyl, ethyl and isopropyl radicals.

The compounds used according to the invention having at least one SiC-bonded group with a Si-bonded hydrogen and a basic nitrogen are, for example, γ-aminoethylaminopropyltrimethoxysilane or γ-aminoethylaminopropylmethyldimethoxysilane or such species. A mixture of silanes can be prepared, for example, by equilibration or condensation with an organopolysiloxane which is free of basic nitrogen but contains Si-bonded hydrogen. The organopolysiloxane used in this case is preferably a methylhydrogenpolysiloxane end-capped with trimethylsiloxy groups or a copolymer of trimethylsiloxy groups, dimethylsiloxane units and methylhydrogensiloxane units.

When carrying out the process according to the invention, compounds containing hydroxyl groups which, by reaction with Si-bonded hydrogen, cause formation of forms and crosslinking of organopolysiloxanes having SiC-bonded groups with basic nitrogen, can include water, ethane, etc. Preference is given to alcohols containing at least two hydroxyl groups per molecule, such as lene glycol, glycerin or triethanolamine, and organopolysiloxanols, such as organosilanols and dimethylpolysiloxanol.

Preferably, the hydroxyl group-containing compound which, upon reaction with Si-bonded hydrogen, causes form formation and cross-linking of the organopolysiloxane having SiC-bonded groups with basic nitrogen, is a compound containing Si-bonded hydrogen 1
Amounts of 1 to 20 gram equivalents of hydroxyl groups per gram atom are used.

The method according to the invention preferably comprises -20 to +50°C.
and at the pressure of the ambient atmosphere, i.e. at or about 1020 hPa (absolute).

When carrying out the process according to the invention, the elimination of Si-bonded hydrogen is carried out using an anhydrous acid, such as glacial acetic acid, by reaction with Si-bonded hydrogen and the formation of a form containing at least one SiC-bonded group with a basic nitrogen. The delay can be effected by addition before or simultaneously with the addition of the hydroxyl group-containing compound which causes crosslinking of the organopolysiloxane.

The foams produced according to the invention can be used, for example, as hydrophobic building materials and in buildings, land vehicles,
Suitable as insulation in ships and aircraft.

Particularly in the production of insulation materials, the process according to the invention can also be used with clouding agents such as those commonly used in the production of insulation materials. Examples of opacifiers of this type are titanite, titanium dioxide (including rutile), chromium oxide, manganese oxide, zirconium, iron oxide, lead monoxide, as well as carbides of silicon, boron, tantalum or tungsten, metallic aluminum, Tungsten or silicon, or a mixture of at least two such opacifying agents. Clouding agents may be present in amounts up to a total of 60% by weight of the respective foam material.

In addition to silicon compounds which contain both Si-bonded hydrogen and at least one SiC-bonded group with a basic nitrogen in the same molecule, other silicon compounds can also be used together in the process according to the invention.

EXAMPLE 1 a A mixture consisting of 400 g of methylhydrogen polysiloxane end-capped with trimethylsiloxy groups and having a viscosity of about 20 mm ² s ^-1 at 25° C. and 165 g of γ-aminoethylaminopropyltrimethoxysilane is heated under nitrogen. Heat to 140°C for 6 hours. The resulting organopolysiloxane, which is stable under exclusion of air, is a clear, colorless liquid with a viscosity of about 7.5 mm ² ·s ^-1 at 25°C. The organopolysiloxane has an amine value (the number of milliliters of 1N HCl required to neutralize 1 g of material) of 2.63, an amine nitrogen content of 3.7% by weight, and contains 1.1% by weight of Si-bonded hydrogen.

b Add 10 g of water to 28.25 g of organopolysiloxane (its manufacturing method is described in a. above). 1
After ~2 seconds, a vigorous evolution of gas occurs and a foam is obtained, which retains its shape.
The reaction ended after 15 seconds, and the foamed organopolysiloxane was crosslinked.

Example 2 Organopolysiloxane (its manufacturing method is shown in Example 2)
2.5 g of glacial acetic acid per 20 g (described in 1a),
Next, add 7g of water. Gas evolution is slower than in Example 1.

Example 3 Using 5g of glacial acetic acid instead of 2.5g of glacial acetic acid,
Repeat the procedure described in Example 2. Gas evolution is even slower than in Example 1.

Comparative experiment End-capped with trimethylsiloxy group,
To 20 g of methylhydrogen polysiloxane having a viscosity of about 20 mm ² s ^-1 at 25 DEG C. are added first 8.25 g of .gamma.-aminoethylaminopropyltrimethoxysilane and then 7 g of water. The foaming proceeds more slowly than in Example 1, and the foam collapses almost completely before the organopolysiloxane crosslinks.

Example 4 a In a three-necked flask equipped with a stirrer, addition funnel and reflux condenser, 150 g of γ-aminoethylaminopropyltrimethoxysilane were
Potassium hydroxide in 4 g of methanol under stirring
0.2g and average molecular weight approximately 450g/mol and
A mixture consisting of 500 g of polyethylsilicate having a viscosity of 4 mm ² s ^-1 at 25° C. is added. The mixture thus obtained is heated to 100° C. for 6 hours.
After the mixture has been cooled to 30° C., 2.5 ml of 10% by weight hydrochloric acid are added. By heating to 130°C, 1.06 g of the flask contents are distilled off.
Finally, potassium chloride is filtered off.

b 50 parts by weight of an organopolysiloxane containing no Si-bonded hydrogen (the method of preparation of which is described in a. above), 50 parts of an organopolysiloxane (the method of preparation of which is described in Example 1a), 50 parts by weight of an organopolysiloxane (the method of preparation of which is described in Example 1a), methylhydrogen polysiloxane as detailed in Example 1a. A mixture consisting of 50 parts by weight of siloxane, 50 parts by weight of γ-aminoethylaminopropyltrimethoxysilane and 60 parts by weight of powdered titanite.
Add 15g of glycerin to 100g. After 1 to 2 seconds, a strong evolution of gas occurs and a foam is obtained, which retains its shape. The reaction is complete after 15 seconds and the organopolysiloxane is crosslinked. This method provides excellent insulation.

Example 5 The procedure described in Example 4b is repeated using 60 parts by weight of powdered titanium dioxide instead of 60 parts by weight of titanite. An excellent thermal insulation material is obtained as well.

Claims (1)

[Claims] 1. A method for producing a foam material by reacting a Si-bonded hydrogen-containing compound with a hydroxyl group-containing compound, in which at least a portion of the same molecule is used as the Si-bonded hydrogen-containing compound during this reaction. 1. A method for producing a cellular material, characterized in that a material having Si-bonded hydrogen and at least one SiC-bonded group having basic nitrogen therein is used. 2 Equilibration of methylhydrogen polysiloxane end-capped with trimethylsiloxy groups with γ-aminoethylaminopropyltrimethoxysilane as a compound having Si-bonded hydrogen and at least one SiC-bonded group containing basic nitrogen. 2. A method according to claim 1, wherein the method is as obtained by: